This invention relates to an intermittent work conveying apparatus for transport of a series of parts through equispaced work stations and particularly to such apparatus requiring multiple directional positioning of the work.
In various production processes, an article or work product, hereinafter generally referred to as the "part", is moved through a series of work stations for processing of the finished part. In many applications, the work on the part at each work station is automatically established and in some instances, a relatively short period of time may be allotted at each station. A typical example of an automated line is an electrocoating paint system wherein the part is sequentially treated to receive a paint application with the article sequentially processed to established a pre-determined coating thickness and finally processed to dry the applied coating. Each step in the process can be accomplished in relatively short period of time. Thus, the part may typically be processed at each station in a maximum of two to three minutes. The part is moved through the sequential positions or work stations in a stepped manner in one system and in a continuous uninterrupted manner or movement in another system. Continuous paint lines move the part through pretreating tanks, coating tanks and final treating tanks by an in-line conveying system. Generally, lengthy treatment and paint tanks are required to accommodate the sequential and continuous movement through the several stations. Generally, the prior art discloses a continuous conveyor of a chain type with the path of the conveying mechanism providing for the movement of the product in a rather smooth curved path into and from the various treating and painting tanks. Although satisfactory painting has been provided using such standard systems, the systems are large, requiring significant floor spaced and are relatively costly. Thus, the tank or container structure is very large to accommodate the continuous movement of the part through the tank structure while maintaining the product within the appropriate environment and atmosphere for product treatment. Such systems also are relatively costly because of the necessity of using large quantities of materials, such as paint, water and other chemicals associated with the large treatment baths or tanks.
Although an intermittent stepped system can be used to reduce the size of the structure, the movement of the product then requires the appropriate lifting and transfer of the product from one tank to the other. Such a system using conventional conveying mechanisms such as chain-type conveyors and the like also present a complex and costly mechanism.
Further, in view of the short cycle time required in any given station or tank, the loading and unloading of the part in an intermittent system presents further complications. Either a significant number of personnel is required for manual loading and unloading of product or various complex and costly loading and unloading mechanisms have heretofore been required.
Generally, present day technology has involved substantial investment in the machinery for electrocoating systems as well as significant maintenance cost and operating personnel cost, particularly related to the loading and unloading of parts and products.
Various articles and products can of course be coated with electrocoating processes. For example, cabinet panels and any other product which can be provided with an appropriate charge can be treated with an appropriate coating.
The short cycle time of any given station provides for relatively large production which minimizes the part cost and has justified the substantial investments required in the process apparatus.
There is however a very significant demand for improved apparatus permitting improved cycle times as well as more effective and less costly loading and unloading mechanisms and related transfer apparatus.